fix: don't error out on empty profile

Fixes microsoft/vscode#153752

Author: connor4312

.eslintrc.js

@@ -16,7 +16,6 @@ module.exports = {
   rules: {
     '@typescript-eslint/no-use-before-define': 'off',
     '@typescript-eslint/explicit-function-return-type': 'off',
-    '@typescript-eslint/interface-name-prefix': ['error', { prefixWithI: 'always' }],
     'react/display-name': 'off',
     'react/prop-types': 'off',
     'header/header': [

packages/vscode-js-profile-core/src/cpu/model.test.ts

@@ -11,6 +11,17 @@ describe('model', () => {
       expect(buildModel(profiles[i])).toMatchSnapshot();
     });
   }
+
+  it('does not error on empty, profile', () => {
+    buildModel({
+      nodes: [],
+      samples: [],
+      timeDeltas: [],
+      startTime: 1654100488066000,
+      endTime: 1654100490779000,
+      $vscode: { rootPath: '.', locations: [] },
+    });
+  });
 });
 
 const profiles = [

packages/vscode-js-profile-core/src/cpu/model.ts

@@ -229,8 +229,10 @@ export const buildModel = (profile: ICpuProfileRaw): IProfileModel => {
   // time before the first sample, and the time of the last sample is only
   // derived (approximately) by the missing time in the sum of deltas. Save
   // some work by calculating it here.
-  nodes[mapId(samples[timeDeltas.length - 1])].selfTime += lastNodeTime;
-  timeDeltas.push(lastNodeTime);
+  if (nodes.length) {
+    nodes[mapId(samples[timeDeltas.length - 1])].selfTime += lastNodeTime;
+    timeDeltas.push(lastNodeTime);
+  }
 
   // 3. Add the aggregate times for all node children and locations
   for (let i = 0; i < nodes.length; i++) {